INDUCED OSMOTIC ADJUSTMENT IN ALFALFA PLANTS CONFERS TOLERANCE TO WATER STRESS

M. Abid, A. Ferchichi, Kh. D. Bachar, E. Mansour, L. Ben Yahya, A. Ben Khaled

Abstract: South Tunisian oases are characterized by arid environment in which drought is a major limiting factor for growth and crop production. In these conditions, understanding plant adaptation is required in order to preserve such regions from degradation. Four levels of water stress were applied to evaluate the effect of drought in three Medicago sativa populations (Chenini, Gannouch and Tebelbou): 25%; 50%; 75% and 100% of field capacity. Under water deficit conditions, leaves and roots exhibited a higher increase in proline, total soluble sugars, amino acids and potassium. A decrease in dry matter production was observed especially in alfalfa leaves. Chenini population showed the highest increase in different solutes, in contrary Tebelbou seems to be the most affected by drought as it showed lowest values. A close relationship was observed between proline and several osmolytes indicating that it is an important indicator of drought stress tolerance in alfalfa plants.

Keywords: compatibles solutes; drought; Medicago sativa; populations; responses

Date published: 2017-08-30